The German Examined Specification DE 10 2005 014 075 B3 describes a spring-cage terminal block that includes a clamping spring having a supporting arm and an opposite clamping arm designed to include at least one end portion at an acute angle to the supporting arm. To force the clamping arm apart from the supporting arm, a displaceable pusher element is provided which has a conductor lead-through. To realize a very small-sized spring-cage terminal block of this type having adequate spring force, the clamping spring has a loop shape that includes a rear segment that joins the supporting arm and the clamping arm. This rear segment is configured at a conductor insertion opening in the housing and has a conductor lead-through opening in alignment therewith. The pusher element is configured within the loop form of the clamping spring, and the conductor feed-through opening thereof is in alignment with the conductor lead-through opening in the rear segment of the clamping spring.
It may, in fact, be possible to realize such a spring-cage terminal block having a low overall height whereby a clamping spring located therein has a very small design. However, the mechanical stress distribution in the clamping spring in response to the application of force is negatively affected by such a spring-cage terminal block. Moreover, the pusher element makes this spring-cage terminal block complicated to operate, and the many individual components result in a relatively complex design.